Microporous films have been made in the past. Microporous films have small pores through the film which permit passage of objects through the film which have a size less than the pore size, such as water vapor. Objects which have a size greater than the pore size are prevented from passing through the film.
Existing microporous films have been made by use of a particle filler in the film, for example calcium carbonate. The film having the particle filler is stretched such that the particle filler falls out of the film. The stretching tension on the film is relieved and pores remain in the film where the particle filler had been in the film. Stretching methods of making microporous films require manufacturing steps to stretch the film and the amount of stretch must be controlled.
Surgical gowns have been used in the medical community to protect medical personnel from liquids and microorganisms during surgical and other medical procedures. Currently available gowns provide liquid barriers by having reinforced areas in at least a portion of the front and sleeves of a gown. Generally, such barrier materials are non-breathable films. For example, one barrier material currently in use is a polyethylene film which is laminated to a non-woven support material. A gown made entirely of this material is frequently found to be uncomfortable to wear. Although such gowns provide a barrier to liquid and microorganisms in critical areas, such gowns are not completely impervious to either liquids or viruses.
Another factor which influences the ability of a gown to act as an effective barrier to either liquids or viruses is the construction of the gown. In the past, gowns have been frequently constructed using stitching to connect one portion of a gown to another. Such stitching can create holes in the barrier material which may allow liquids or viruses to pass through the material.